Question

Choose the correct answer. 1. A bad smalling gas is mixed with cooking gas.so that; (a)cooking gas burns better in presence of this gas (b)it becomes odouries after buring(C)it helps detect leakage of cooking gas(D)a preevents leakage of cooking gas.

Answer 1

(C) This question is based around methane which is odourless and colourless, certainly when compared with 'town gas' its predecessor. Thus when local gas supplies were changed over from town gas to methane (usually from gas fields) a sulfide or mercaptan was added. You might be interested to know that the addition is a legal requirement in many countries; in the UK, USA and Canada there must be enough 'smell' added to be able to detect about 1% in the air whereas in Japan it must be enough to smell 0.1%.